WO2008155376A1

WO2008155376A1 - Pylon for coupling an engine for an aircraft having a rear engine attachment beam forming a rudder control bar

Info

Publication number: WO2008155376A1
Application number: PCT/EP2008/057768
Authority: WO
Inventors: Eric Haramburu; Laurent Sammito; Jean Larrochelle
Original assignee: Airbus France
Priority date: 2007-06-20
Filing date: 2008-06-19
Publication date: 2008-12-24
Also published as: US8226029B2; ATE508940T1; FR2917712A1; FR2917712B1; EP2167384B1; US20100170980A1; EP2167384A1

Abstract

The invention relates to a pylon for coupling an engine for an aircraft comprising a rigid structure (10) forming a casing and a system for mounting the engine (11) mounted on the structure (10) and comprising a rear engine attachment (8) comprising an attachment body (42) on which at least one clevis (52) is articulated also designed to be articulated on the engine (2), the system for mounting the engine (11) also comprising a device (9) for absorbing the thrust forces generated by the engine (2), comprising two lateral link rods connected to a rudder control bar mounted articulated relative to the casing. According to the invention, the attachment body (42) forms the said rudder control bar, the body (42) being mounted articulated relative to the casing (10) with the aid of an articulation axis system.

Description

ENGINE ATTACHING MACHINE FOR AN AIRCRAFT HAVING A REAR ENGINE ATTACHING BEAM FORMING PALONNIER

DESCRIPTION

TECHNICAL AREA

The present invention relates generally to an aircraft engine assembly, of the type comprising a motor, an attachment pylon, and an engine mounting system provided with a plurality of engine attachments and being interposed between a Rigid structure of the engine mount and the engine.

The invention also relates to such an aircraft engine mounting pylon.

The invention can be used on any type of aircraft equipped for example with turbojet engines or turboprop engines.

This type of attachment pole, also called "EMS" (of the English "Engine Mounting Structure"), allows for example to suspend a turbine engine below the wing of the aircraft, or to mount this turbine engine at above this same sail.

STATE OF THE PRIOR ART

Such a rigging mast is in fact provided to form the connecting interface between an engine such as a turbojet and a wing of the aircraft. It makes it possible to transmit to the structure of this aircraft the forces generated by its associated turbojet engine, and also authorizes the routing of fuel, electrical, hydraulic, and air systems between the engine and the aircraft.

To ensure the transmission of forces, the mast has a rigid structure, also called primary structure and often of the "box" type, that is to say formed by the assembly of upper and lower spars and two side panels interconnected via transverse ribs.

On the other hand, the mast is provided with an engine mounting system interposed between the turbojet engine and the rigid structure of the mast, this system generally comprising at least two engine fasteners, generally a front attachment and a rear attachment.

In addition, the mounting system comprises a device for taking up the thrust forces generated by the turbojet engine. In the prior art, this device takes for example the form of two lateral connecting rods connected on the one hand to a rear part of the turbojet fan housing, and on the other hand to a rudder, itself mounted hinged to a body rear engine mount attached to the box.

Similarly, the attachment mast also includes a second mounting system interposed between the rigid structure of the mast and the wing of the aircraft, the second system usually consisting of two or three fasteners.

Finally, the mast is provided with a secondary structure ensuring the segregation and maintenance of systems while supporting aerodynamic fairings.

In the embodiments of the prior art, the engine mounting system comprises a rear engine attachment whose body is, as mentioned above, directly attached to the lower spar of the box, with which it is usually in contact. The attachment body, also called transverse beam, also carries in an articulated manner the rudder, which receives at its ends the rods for resumption of thrust forces, as is known from documents EP 1 136 355 and US 6 494 403.

This configuration involves various drawbacks among which there is in particular the complexity of design of the rear part of the engine mounting system, which results in significant assembly and dismantling times, and therefore expensive. In addition, this configuration leads to a large footprint constituting a major obstacle in the flow zone of the secondary flow, and therefore causes significant aerodynamic disturbances. Aerodynamic disturbances encountered at the rear engine attachment cause drag resulting in loss of performance of the aircraft. Finally, we note that another disadvantage of this type of embodiment, in which the spreader is hinged to the rear engine attachment beam itself attached to the lower beam of the primary structure, lies in the accumulation of several paths d 'Separate efforts on the same rear engine attachment, making its design quite complicated. SUMMARY OF THE INVENTION

The object of the invention is therefore to propose an aircraft engine attachment pylon that at least partially overcomes the disadvantages mentioned above, relative to the embodiments of the prior art.

To do this, the subject of the invention is an attachment pole for an aircraft engine, said mast comprising a rigid structure forming a caisson and an engine mounting system mounted on said rigid structure and comprising in particular a rear engine attachment. comprising a fastening body on which is articulated at least one shackle also intended to be hinged to the engine, said engine mounting system further comprising a device for taking up the thrust forces generated by the engine, comprising two connected lateral rods at their rear end to a spreader mounted articulated relative to said box. According to the invention, said attachment body of the rear engine attachment constitutes said lifter on which said two lateral connecting rods are connected, said attachment body being articulated with respect to said box by means of a system of hinge axis.

The particularity of the invention therefore lies in the fact of mounting the body of the rear engine attachment in an articulated manner with respect to the rigid structure forming a box, so that it simultaneously forms the rudder of the force recovery device thrust incorporating the lateral rods. By this double function of the attachment body, a significant simplification of the design of the rear part of the engine mounting system, as well as a smaller footprint. The engine mounting and dismounting times on the mast are therefore reduced, and aerodynamic disturbances of the secondary flow minimized.

Preferably, said attachment body is hingedly mounted on a support fitting fixedly mounted on said box, said support fitting incorporating a pin belonging to said hinge pin system, and housed in a corresponding hole of said attachment body . Naturally, it is also possible to provide an inverted arrangement in which the pin is carried by the fastener body and the corresponding orifice formed in the support fitting, without departing from the scope of the invention. Likewise, another conceivable solution would be to provide the hinge pin system passing through each of the fastening bodies and support fitting.

In the preferred case where the hinge pin system, and therefore in particular the aforementioned pin, is arranged in the vertical direction, the cooperation between this pin and the corresponding hole makes it possible to ensure the recovery of the forces exerted according to the longitudinal and transverse directions. Preferably, the attachment pylon also comprises a tie-rod system making it possible to retain said attachment body with respect to the support fitting in the direction of an articulation axis of the rudder defined by said axis system, said pulling system passing through each of said attachment bodies and support fitting, as well as said pawn pin hollow. Thus, this pulling system makes it possible to complete the rear engine attachment by ensuring the recovery of the forces exerted in the vertical direction, when arranged in the same direction.

Preferably, said attachment body has two receiving means cooperating respectively with the two lateral connecting rods, said two receiving means being arranged, in front view, on either side of the articulation pin system, and for the known purpose of obtaining an equal distribution of the forces passing through the connecting rods of the thrust forces. In such a configuration, it is provided that said two receiving means each take the form of a clevis made in one piece with said fastener body.

Still preferably, the attachment mast comprises abutment means mounted on the rigid structure forming a box and positioned so as to stop, in both directions, the rotation of the rudder about its axis of articulation defined by said system. axis.

Thus, in the event of a failure at this recovery device, which may for example take the form of a break rod or an axis establishing the connection between one of these rods and the rudder, the rotation of the latter , constituted by the rear engine attachment body, can be stopped by the stop means provided for this purpose. When such a situation occurs, the recovery of thrust forces is then advantageously ensured by one of the only two connecting rods, in combination with the abutment (s) between the rudder and the stop means judiciously positioned.

Preferably, said support bracket comprises two lateral projections housed with clearance respectively in two slots formed in said attachment body, said slots and projections jointly forming said stop means. It could alternatively be envisaged to provide the projections on the spreader and the corresponding slots on the support fitting, without departing from the scope of the invention.

More generally, it is expected that the abutment means comprise lateral projections integral with the primary structure and cooperating respectively with lateral slots formed in the fastener body, or vice versa.

Alternatively, the lateral projections may be carried by the axis system and cooperate respectively with lateral slots provided on the attachment body, or vice versa.

Finally, they may alternatively comprise at least one abutment element which on the one hand passes through the fastener body being integral with it, and on the other hand through the axis system with play, said abutment element being able to pivot freely with the attachment body according to the axis of the rudder until it has consumed the clearance between the same abutment element and said axis system, which then makes it possible to block the rotation of the attachment body when a failure. Conversely, said at least one stop member could be secured to the axis system and mounted with clearance through the fastener body, for which it could then constitute an abutment following excessive pivoting of the body, reflecting a failure.

Preferably, as mentioned above, said hinge axis system is arranged substantially vertically, thus substantially parallel to the transverse plane of the beam-shaped rear engine attachment body.

Finally, it is expected that said box is formed by the assembly of an upper spar, a lower spar, two side panels and transverse ribs connecting said spars and panels, said rear rudder engine attachment body being located under said lower spar. This applies in the preferred case where the engine is intended to be suspended under the wing of the aircraft.

The invention also relates to an engine assembly for aircraft comprising a mast such as that just presented, and a motor attached to the mast.

Finally, it relates to an aircraft comprising at least one such engine assembly. Other advantages and features of the invention will become apparent in the detailed non-limiting description below.

BRIEF DESCRIPTION OF THE DRAWINGS

This description will be made with reference to the appended drawings among which; FIG. 1 represents a partially schematic side view of an aircraft engine assembly, comprising an attachment pylon according to a preferred embodiment of the present invention; FIG. 2 represents a detailed partial perspective view of the rear part of the engine mounting system, belonging to the mast shown in FIG. 1;

- Figure 3 shows a longitudinal sectional view through the plane of symmetry P of Figure 2;

- Figure 4 shows a sectional view through the horizontal plane Pl of Figures 2 and 3, the left half-section showing the normal configuration said undegraded, and the right half-section showing the so-called degraded configuration, adopted more at the break of one of the lateral rods of recovery of the thrust forces;

FIG. 5 shows a view similar to that of FIG. 2, with the rear part of the engine mounting system made according to another preferred embodiment of the present invention;

- Figure 6 shows a longitudinal sectional view through the plane of symmetry P of Figure 5; and

- Figure 7 shows a sectional view through the horizontal plane P1 of Figures 5 and 6.

DETAILED PRESENTATION OF PARTICULAR EMBODIMENTS

With reference to FIG. 1, there is seen a motor assembly 1 for an aircraft intended to be fixed under a wing 3 of this aircraft, this assembly 1 object of the the present invention being provided with an attachment pylon 4 in the form of a preferred embodiment of the present invention.

Overall, the engine assembly 1 comprises a motor such as a turbojet engine 2 and the attachment pylon 4, the latter being notably provided with a rigid structure 10 and a mounting system of the engine 11 composed of a plurality engine fasteners 6, 8 and a device for taking up the thrust forces 9 generated by the turbojet engine 2, the mounting system 11 thus being interposed between the engine and the aforementioned rigid structure 10, the latter also being referred to as the primary structure . As an indication, it is noted that the assembly 1 is intended to be surrounded by a nacelle (not shown), and that the attachment pylon 4 comprises another series of fasteners (not shown) to ensure the suspension of this assembly 1 under the wing of the aircraft.

Throughout the description, by convention, X is the longitudinal direction of the mast 4 which is also comparable to the longitudinal direction of the turbojet engine 2, this direction X being parallel to a longitudinal axis 5 of the turbojet engine 2. On the other hand, Y denotes the direction oriented transversely to the mast 4 and also comparable to the transverse direction of the turbojet 2, and Z the vertical direction or height, these three directions X, Y and Z being orthogonal to each other. On the other hand, the terms "before" and

"Backward" are to be considered in relation to a direction of advancement of the aircraft encountered following the thrust exerted by the turbojet engine 2, this direction being shown schematically by the arrow 7. In FIG. 1, it can be seen that only the recovery device 9, the engine fasteners 6, 8, and the rigid structure 10 of the attachment pylon 4 have been shown. The other non-represented constituent elements of this mast 4, such as the attachment means of the rigid structure 10 under the wing of the aircraft, or the secondary structure ensuring the segregation and maintenance of the systems while supporting aerodynamic fairings , are conventional elements identical or similar to those encountered in the prior art, and known to those skilled in the art. Therefore, no detailed description will be given.

The turbojet engine 2 has at the front of a large fan casing 12 delimiting an annular fan duct 14, and has a rear casing 16 of smaller dimension, enclosing the heart of this turbojet engine. Finally, the central casing 16 is extended towards the rear by an ejection casing 17 of larger size than that of the casing 16. The housings 12, 16 and 17 are of course integral with each other.

As can be seen in FIG. 1, the system 11 consists of a front engine attachment 6, a rear engine attachment 8 and a fastener 9 forming a device for taking up the thrust forces generated by the turbine engine 2. As is schematically shown in Figure 1, the device 9 takes the form of two lateral rods (only one being visible due to the side view) connected on the one hand to a rear portion of the fan casing 12, and secondly to a mounted lifter articulated relative to the box 10, as will be detailed below.

The front engine attachment 6 is secured to the fan casing 12, and is for example designed so as to take up the forces generated by the turbojet engine 2 in directions Y and Z, using shackles / rods. As an indication, this front attachment 6 preferably penetrates into a circumferential end portion of the fan casing 12.

The rear engine attachment 8 is a feature of the invention and will be more fully detailed with reference to the following figures. It is generally interposed between the ejection housing 17 and the rigid structure 10 of the mast. It is in turn designed so as to be able to take up the forces generated by the turbojet engine 2 in the Z direction, as well as those exerted in the X and Y directions thanks to its particular cooperation with the recovery device 9, which will be exposed below.

Still with reference to Figure 1, it can be seen that the structure 10 has the shape of a box extending in the X direction, this box being also called torsion box. It is conventionally formed by an upper spar 26 and a lower spar 28, as well as by two panels laterally (only one being visible in Figure 1) extending both in the direction X and substantially in a plane XZ. Inside this box, transverse ribs 32 arranged in YZ planes and spaced longitudinally reinforce the rigidity of the box. It is noted for information that the elements 26, 28 and 30 can each be made in one piece, or by the assembly of contiguous sections, which may optionally be slightly inclined relative to each other. Here, the lower spar 28 preferably extends in a plane inclined relative to the horizontal, over its entire length, as shown in Figure 1. The inclination is such that the lower spar 28, parallel to the Y direction , approaches the axis 5 going backwards, in order to approach the ejection housing 17 to allow the introduction of the rear engine attachment 8 on the same housing 17. Preferably, all the elements forming the box are made of composite materials comprising a mixture of resin and glass fibers and / or carbon.

Referring to Figures 2 to 4, we can see a portion of the rear engine attachment 8 and the thrust load recovery device 9, some elements have been deliberately omitted, for obvious reasons of clarity.

The rear engine attachment 8 comprises a body 42 comparable to a transverse beam made in one piece, and mounted on the box 10 in a particular way to the present invention, which will be detailed below. Like all of the rigid structure 10, this body 42 arranged under the lower spar 28 has the plane P, oriented along the X and Z directions, as a plane of symmetry. At opposite lateral ends, the body 42 comprises a yoke 50 on which is articulated a shackle 52 by means of an axis 54 oriented in the direction X. As an indication, a second axis 55 oriented in the X direction is also provided between these two elements, but mounted with clearance so as to be operative only in case of failure / breakage of the link formed with the aid of the axis 54. This ensures a safety function "Fail Safe" for the transmission of forces in direction Z.

In addition, another axis 56 oriented in the X direction is also provided at a lower end of the shackle 52, so as to articulate the latter on a bracket / yoke 57 fixedly mounted on the casing 17 of the turbojet 2.

One of the peculiarities of the present invention consists in mounting the attachment body 42 in an articulated manner with respect to the casing 10, along an axis of articulation 59 passing through the plane of symmetry P. To do this, it is all initially provided a support bracket 60 plated at its flat upper surface against the lower beam 28, externally relative to the housing 10. The bracket 60, fixedly mounted in a conventional manner on the lower beam 28, ends down by a hollow pin 62 oriented along the axis 59. It forms, with a hollow pin annex 64 preferably concentric and arranged internally relative thereto, a hinge pin system 66 of the attachment body 42 on the box 10. As is best seen in Figure 3, the the upper end of the hollow pin 64 appendix takes the form of a shoulder 69 bearing against the inner surface of the spar 28, the body of this annex pin in effect the same spar 28, and the support bracket 60. The system of axis 66 oriented along the vertical axis 59 is housed in a corresponding orifice 68 formed in the attachment body 42, and opening upwards. As a guide, it is noted that to facilitate the oscillatory rotational movements of the fastener body 42 around the axis system 66, elements 70 with a low coefficient of friction are interposed between the contact surfaces.

The cooperation between the orifice 68 and the hollow pin 62 of the axis system 66 makes it possible to take up the forces exerted along the X and Y directions. In addition, the annex pin 64 makes it possible to resume efforts exerting according to these same directions in case of failure / rupture of the pin 62. This advantageously allows to provide a security function called "Fail Safe" for the transmission of forces along the X and Z directions. Moreover, it is noted that so that this path of forces passing through the hollow pin 64 is only operating during a failure / rupture of the pin 62, a functional clearance is then preferably provided between the two concentric pins 62, 64. As mentioned above, the hinge pin system 66 thus consists of an outer axis 62 cooperating closely with said central orifice 68, and an internal axis 64 said "pending", which is installed with play inside the outer axis 62. This ensures a redundancy of the path of the forces transmitted by the axis system 66, and thus allows to ensure the safety function "Fail Safe", as it comes from 'to be present. Nevertheless, it would alternatively be possible to provide, without departing from the scope of the invention, a solution in which the hinge axis system consists of two contiguous symmetrical half-axes ensuring the redundancy of the force path, given in the event of a failure occurring on one of the half-axes, the forces are then transmitted by the other non-failing half-axis. On the other hand, another possible design would be to provide the axle system integral with the rear engine attachment beam, and the corresponding central orifice on the primary structure.

To maintain the fastening body 42 in the Z direction relative to the box and to the support bracket 60 fixed thereto, there is provided a tie rod 74 internally through the hollow hollow pin 64, as well as the fastener body 42 Consequently, it also passes through the support fitting 60 and the orifice 68, as can be seen in FIG. 3. To ensure the vertical support, the tie rod 74 has at its upper end a shoulder 76 bearing against the said shoulder 69, and at its lower end projecting downwards. relative to the body 42, a threaded portion cooperating with a nut 77 pressed against the same body 42. Thus, the tightening of the nut 77 is performed to obtain a very small clearance between the end of the system of 66 and the bottom of the corresponding orifice 68, and / or between the upper end of the body 42 and the support fitting 60.

The tie rod 74 forms with a tie rod 78 a drawbar system 79 oriented along the vertical articulation axis 59, the tie rod 78 being preferably arranged concentrically and internally with respect to the tie rod 74. The tie rod 78 has at its upper end a shoulder 80 bearing against the shoulder 76 above, and at its lower end projecting downwardly relative to the tie rod 74, a threaded portion carrying a nut 81 cooperating with the lower end of the tie rod 74.

As can be seen in FIG. 3, the hollow and concentric elements 64, 74, 78 pass through the lower spar 28, implying that their shoulders 69, 76, 80 are situated inside the caisson, and superposed while in contact with each other in pairs. .

The presence of the tie rod 74 makes it possible to ensure the recovery of the forces exerted in the direction Z. In addition, the tie rod 78 makes it possible to take up the forces exerted according to this same direction in the event of failure / breakage of the tie rod 74. This advantageously makes it possible to provide a safety function called "Fail Safe" for the transmission of forces along this direction Z. Moreover, it is noted that for that this path of forces passing through the tie rod 78 is only operating during a failure / breakage of the tie rod 74, then a functional clearance is preferably provided between the nut 81 and the lower end of the tie rod 74.

Thus, there is provided a pulling system 79 which is housed inside the axis system 66, and which generally allows to retain the motor attachment body 42 in the Z direction. 66 axis, the pulling system 79 consists of two tie rods capable of working together or independently, to ensure the redundancy of the effort path. In a first solution, corresponding to that shown in Figure 3, the two tie rods 74, 78 can be contiguous and work together. Alternatively, it would be possible to provide that only the outer tie rod 74 is working, with the tie rod 78 "waiting" inside the external tie rod 74, that is to say, providing a clearance between the nut 81 and the lower end of the outer tie rod 74. On the other hand, it is specified that a reverse arrangement could be adopted, in which the pulling system would be integral with the rear engine attachment beam, without departing from the scope of the invention. 'invention.

In addition, it is stated that the recovery of the moments exerted in the X and Y directions is effected by means of the hinge axis system 66, by its biasing in flexion. The articulation of the rear engine attachment body 42 with respect to the box 10 is specifically provided so that this body simultaneously performs the role of lifter of the thrust force recovery device, as will now be detailed, still with reference to Figures 2 to 4. The device 9 comprises generally two lateral rods of recovery efforts of thrust 90, each of these rods having a front end

(Not shown in these figures) connected to the fan casing 12, for example on or near a horizontal median plane of the turbine engine 2.

The two lateral links 90, disposed on either side of the plane P, each have a rear end 90a connected to a spreader formed by the body 42, which is therefore articulated along a vertical axis 59 passing through the plane P.

A mechanical connection, constituting the connection through which the thrust forces in normal mode are intended to transit, is achieved by means of a hinge pin 92 connecting the rear end 90a with receiving means in the form of a clevis 94 made in one piece with the body 42. Preferably, the two axes 92 are orthogonal to the plane of the connecting rods 90, and arranged, in front view, on either side of the system. articulation pin 66 and its axis 59.

Referring more particularly to Figure 4, it can be seen that the mast 4 comprises stop means suitably positioned so that in case of failure of the recovery device 9, for example may take the form of a rupture of the one of the rods 90 or a break of one of the axes 92, the rotation of the lifter 42 is stopped by these means.

In the preferred embodiment described, the stop means take the form of two arrangements arranged symmetrically with respect to the plane P, each arrangement comprising a lateral projection 96 forming an integral part of the fitting 60, housed with play in a vertical slot 97 practiced. in the attachment body 42 forming a lifting beam, and opening upwards.

Thus, in normal operation, the protrusion 96 extending vertically and laterally does not normally abut on the wall of the slot 97 in which it remains inserted, as can be seen in the half-view on the left of FIG.

On the other hand, when a failure of the type indicated above occurs, the spreader bar 42 which is no longer connected only by a single connecting rod 90 pivots along the axis 59 until one of its lateral ends comes into position. contact of its projection 96 corresponding, forming stop means. More precisely and as shown in the half-view on the right of FIG. 4, it is one of the vertical walls of the slot 97 which abuts against its corresponding projection 96.

Therefore, it should be understood that the positioning of the stops is retained so as to impose a maximum angle A of rotation of this spreader about the axis 59, this maximum angle A, preferably identical for both directions of rotation, being naturally determined so that the function of resumption of the thrust forces can always be provided by the recovery device 9, at least for a given period.

Finally, it is indicated that the abovementioned abutment means can also serve, when they are in the abutment configuration, the resumption of the moments exerted in the X and Y directions, together with the aid of the axis system. hinge 66 biased in flexion. Referring now to Figures 5-7, the rear portion of the engine mounting system can be seen in accordance with another preferred embodiment of the present invention. It is of a design substantially similar to that presented above, in particular being specified that in the figures, the elements bearing the same reference numerals correspond to identical or similar elements.

Thus, it can be seen that the main difference with the previous embodiment lies in the design of the stop means, positioned so as to stop, in both directions, the rotation of the spreader 42 about its axis of articulation 59 defined by the axis system 66.

Indeed, there is provided one or more stop elements 101, preferably taking the form of a pin oriented in the direction X, and passing right through the attachment body 42, passing through the axis of articulation 59. The stop element 101 has a front end secured to a front flank of attachment body 42 from which it projects forward, and a rear end secured to a rear flank of attachment body 42 from which it projects rearwardly.

The stop element 42, for example cylindrical and orthogonal to the hinge axis 59 that it intercepts, passes with play each of the pulling system 79 and axis system 66. To do this, the axis system 66 has a passage 103 diametrically crossing its two hollow shafts 62, 64, which therefore has a diameter greater than that of the pin 101. In the same way, the pulling system 79, which is here represented only with a single tie rod 74, has a passage 105 diametrically crossing its tie rod 74, which passage also has a diameter greater than that of the pin 101, and preferably also greater than that of the passage 103.

Thus, in normal operation, the pin 101 passes through the passages 103 and 105 without being in contact with them, which firstly gives rise to a circumferential clearance 107, with respect to the axis 59, between each pin end 101 and the passage 103. The two sets 107, provided diametrically opposed on the axis system 66, is large enough to allow the low rotations of the spreader 42 during normal operation, during which the thrust rods 90 are each solicited and non-failing.

In contrast, when a failure of the type indicated above occurs, the lifter 42 which is no longer connected by a single rod 90 rotates along the axis 59 by driving the pin 101 which follows the same movement, until what this pin 101 comes to contact passage 103, at both ends. The double contact established following the consumption of the two games 107 then makes it possible to activate the abutment means and induces a rotational locking of the spreader, due to the permanent rotation locking of the axis system 66 with respect to the rigid structure of the mast.

Here again, it should be understood that the positioning and dimensioning of the abutment means are retained so as to impose a maximum angle of rotation of this rudder about the axis 59, this maximum angle, preferably identical for both directions of rotation. rotation, being naturally determined so that the function of recovery of thrust forces can be provided by the recovery device 9 despite the failure of the rod, and this at least for a specific period.

In addition, it is specified that the design retained is such that the rotation of the spreader 42 causes a contact of the pin 101 with the passage 103 before the pin 101 comes into contact with the other passage 105, made on the pulling system 79. This makes it possible to pass the thrust forces, in failure mode, by the axis system 66 provided for this purpose, and not by the pulling system 79 essentially designed to ensure the suspension of the body of fastener 42.

In this regard, it is noted that in normal operation, the pin 101 therefore passes through the passages 103 and 105 without being in contact with them, which also leaves a clearance 109 along the axis 59, between each end of pin 101 and the passage 105. Thus, the recovery of forces in the direction Z parallel to the axis 59 is effected by the abutment of the lower end of the tie rod 74 with the nut 77, the pin 101 then remaining inoperative due to the presence of the two games 109.

On the other hand, when a failure of the abutment connection between the nut and the tie rod 74 occurs, there is a relative displacement along the axis of articulation 59 between the tie rod 74 and the rudder bar 42, until the pin 101 comes into contact with the passage 105, at both ends. The double contact established following the consumption of the two vertical games 109 then activates a stop, and induces a locking in translation of the rudder relative to the tie rod 74. The activated abutment is then an integral part of the path of recovery of vertical forces in failed mode.

Of course, various modifications may be made by those skilled in the art to the aircraft aircraft turbojet engine attachment pylon 4 which has just been described, solely by way of nonlimiting example. In this respect, it is possible in particular to indicate which if the mast 4 has been presented in a configuration adapted to be suspended under the wing of the aircraft, this mast 4 could also be in a different configuration allowing it to be mounted above this same sail.

Claims

An attachment mast (4) for an aircraft engine (2), said mast comprising a rigid box structure (10) and an engine mounting system (11) mounted on said rigid structure (10) and comprising in particular a rear engine attachment (8) comprising a fastening body (42) on which is articulated at least one shackle (52) also intended to be articulated on the engine (2), said engine mounting system (11) further comprising a device (9) for taking up the thrust forces generated by the engine (2), comprising two lateral links (90) connected at their rear end (90a) to a spreader hinged with respect to said box (10), characterized in that said attachment body

(42) of the rear engine attachment (8) constitutes said lifter on which said two lateral connecting rods (90) are connected, said attachment body (42) being articulated with respect to said box (10) by means of a hinge pin system (66).

2. Hitching mast (4) according to claim 1, characterized in that said fastening body (42) is hingedly mounted on a support bracket (60) fixedly mounted on said box (10), said support bracket incorporating a pin (62) belonging to said hinge axis system (66), and housed in a corresponding hole (68) of said hinge body (42).

3. Hitching mast (4) according to claim 2, characterized in that it comprises a pulling system (79) for retaining said fastening body (42) relative to the support fitting (60) according to the direction of an articulation axis (59) of the spreader defined by said spindle system (66), said pulling system (79) passing through each of said attachment bodies (42) and support fitting (60), and said hollow pin (64).

4. latching mast (4) according to any one of the preceding claims, characterized in that said fastening body (42) has two receiving means cooperating respectively with the two lateral rods (90), said two means of reception being arranged, in front view, on either side of the hinge axis system (66).

5. Hitching mast (4) according to claim 4, characterized in that said two receiving means each take the form of a yoke (94) formed integrally with said attachment body (42).

6. Hitching mast (4) according to any one of the preceding claims, characterized in that it comprises stop means mounted on the rigid structure (10) forming box and positioned so as to stop in the two sense, the rotation of the spreader (42) around its axis articulation member (59) defined by said axis system (66).

7. Hitching mast (4) according to claim 6 combined with claim 2, characterized in that said support bracket (60) comprises two lateral projections (96) housed with play respectively in two slots (97) formed in said fastener body (42), said slots and projections jointly forming said stop means.

8. attachment mast (4) according to any one of the preceding claims, characterized in that said hinge axis system (66) is arranged substantially vertically.

9. Engine assembly (1) for aircraft characterized in that it comprises a latching mast (4) according to any one of the preceding claims, and a motor (2) fixedly mounted on said mast.

Aircraft comprising at least one engine unit (1) according to claim 9.